In an effort to reduce illegal immigration from Mexico, the U.S. government is airlifting immigrants captured in remote desert areas of the state of Arizona to less arid border regions of Texas. Then the immigrants are returned to Mexico from there. Border Patrol officials say this policy will reduce deaths in the desert.

It used to be described as a revolving door. Immigrants captured after crossing the border in southern Arizona were repatriated back to Mexico at a nearby border crossing. Border Patrol agents would often catch those same immigrants again in the coming days.

Now, the Border Patrol is chartering jet airplanes to fly the captured immigrants hundreds of kilometers away to Texas border crossings. The immigrants can then either try to cross in the relatively safer areas along the Texas border, or they can trek all the way back to the Sonoran desert along the Arizona border.

The hope of U.S. officials is that many of them will give up, and thereby not put themselves in danger in the hostile desert area. Human Rights groups and migrant activists, however, say this policy just causes more hardship for poor people seeking work in the United States.

Border Patrol spokesmen in Arizona say the airlift program is both a law enforcement and a humanitarian measure. Every year, dozens of migrants die in the desert area along the border in an area near the Arizona city of Tucson, because of the intense heat and lack of water. Most have been abandoned on the trail by people smugglers. Border Patrol agent Patricia McGurk in Tucson says airlifting detained immigrants far away keeps them from going back to the people who got them in trouble in the first place.

"When you take them back into the same area, what they are doing is going right back to the same smugglers who left them out there to die," she said. "We do not want to do that. We want to get them away from the smuggling organizations."

Agent McGurk says smugglers are making millions of dollars every year by herding people across the border and pointing them north. Some immigrants make it, some are captured and some die. She says the smugglers are even resorting to stimulant drugs, like ephedra, that keep the migrants awake and moving faster over the rough trails. This, she says, has caused even more deaths.

"The migrants are dying one or two miles into the United States," explained Ms. McGurk. "That is telling us that they are getting pushed so hard by the smugglers that they are just expiring. These pills, obviously, they [the smugglers] give them to them [the migrants] to make them go faster, but drugs like ephedra, they dehydrate you."

In response to this, Agent McGurk says the Border Patrol has increased its rescue and emergency medical capabilities.

More than 130 immigrants have died so far this year in the Tucson sector. Heat exposure was the cause of death in more than half of those cases. There have been far fewer deaths along the eastern Texas border. Because of this, the Border Patrol views the airlift of immigrants to Texas from Arizona as a humanitarian effort.

But immigrant advocates see it differently. Jonathan Jones of Proyecto Libertad, a privately funded legal services group in Harlingen, Texas, says U.S. immigration policy is to blame for the dangers immigrants face.

"Border Patrol wants to couch some of its activity as a sort of humanitarian kind of thing, but it is more public relations than anything else," said Mr. Jones. "The fact is that, because of increased enforcement there is increased risk all along the border."

Mr. Jones says stepped up enforcement in safer areas caused immigrants to cross in unsafe sectors. He says flying immigrants hundreds of kilometers from where they started puts an economic, as well as a physical burden on them. He acknowledges that the Border Patrol is only trying to do its job, and he says it is U.S. lawmakers who need to come up with a better system.

"The disagreement, of course, would be with Congress," he said. "In fact, our enforcement policy just exacerbates a situation, and will not ever make it vanish and go away.

"It just simply exacerbates the phenomenon of migration," continued Mr. Jones. "This is just one of those little policy strategies that creates a lot of pain for everybody, and that is about all there is to that."

Mr. Jones and other immigration activists favor some form of legalization for migrants seeking work in the United States. This is also favored by the Mexican government. There have been various proposals for a guest worker program, or some form of amnesty. But the terrorist attacks on New York and Washington two years ago have increased the calls to secure the borders. With an election year ahead in the United States, most observers see little opportunity for a change in U.S. immigration policy in the immediate future.